The successful architect Robert Kant, breathless manager for major projects in the Far East, wants to jet to Shanghai for a business meeting with his ambitious partner and future wife Lotta. When checking in, he notices that he is missing important papers and has to go back to the office. In the absence of a taxi, he got hold of an abandoned rental car and accelerated. There is a serious accident with the potter Teresa. A complete load of valuable ceramic tableware breaks, but it seems like miraculously nobody is injured. Teresa would now like to know the insurance number of the other party involved in the accident, but he has lost memory and doesn't even know his name anymore. The police simply call him Cheng - that was the name of the last tenant of the rental car. Since the confused does not know where to go, Teresa takes him in for the time being. The single mother turns out to be downright chaotic. She has notorious financial problems, is moody, and can do without the wise advice of her new roommate. Nevertheless, the two are magically drawn to each other: they even like the same jokes. For Teresa's bright children Max and Lisa, Cheng will soon be a father substitute. When Robert returns to the scene of the accident and finds his ID, he is not even so sure whether he even wants to go back to his old life.